Calorimeter
CWD PLUS
The CWD PLUS is a high-precision combustion calorimeter designed for the direct and continuous determination of gas quality. As part of the CWD series – Calorimetry, Wobbe Index and Specific Gravity – the system determines key gas quality parameters including calorific and heating value, Wobbe index, specific density, and CARI (air requirement).
The CWD PLUS has been specifically developed for applications requiring increased measurement accuracy. In natural gas applications, it achieves an accuracy of ±1.0% relative to the measured value, enabling precise and reliable monitoring of the Wobbe index and consistent control of gas quality.
Thanks to its various measurement ranges, the CWD PLUS can be flexibly adapted to different gas compositions and industrial processes. Typical applications include natural gas, biomethane, liquefied petroleum gas (LPG), refinery gases, flare gases, and fuel gases.
Its versatility makes the CWD PLUS particularly suitable for fuel control in refineries, power generation from refinery gases, and process monitoring and control in the glass industry, as well as other industrial applications where accurate and continuous gas quality measurement is essential.
| Application | Wobbe Index Range Min (MJ/m³) | Wobbe Index Range Max (MJ/m³) | Accuracy |
|---|---|---|---|
| LPG-Air for Appliances | 30 | 80 | 1 FSR |
| Biogas | 14.5 | 25 | 1 FSR |
| Coke Oven Gas | 19 | 29 | 1 FSR |
| Flare Gas | 0 / 0 / 0 / 7.5 | 118 / 90 / 90 / 90 | 2 FSR / 2 FSR / 2 FSR / 2 FSR |
| Fuel Gas | 0 / 5 / 5 / 20 / 0 / 0 / 10 | 75 / 30 / 60 / 40 / 30 / 30 / 40 | 2 FSR / 1 FSR / 1 FSR / 1 FSR / 1 FSR / 1 FSR / 1 FSR |
| LPG-Air | 60 / 30 | 85 / 60 | 1 FSR / 1 FSR |
| Mixed Gas | Various Mixed Gases | Details available on request | |
| Natural Gas | 30 | 60 | 1% of measured value |
| Refinery Gas | 25 | 70 | 1 FSR |
| Parameter | Value |
|---|---|
| Weight | Approx. 54 kg |
| Dimensions (H × W × D) | 1020 × 720 × 337 mm |
| Protection Rating | IP50 |
| Ambient Temperature | 5–40 °C |
| Permissible Temperature Change | ≤ 5 °C per hour |
| Ambient Humidity | 0–95% Relative Humidity |
| Ambient Pressure | 800–1100 hPa (0.8–1.1 bar) |
| Gas Inlet Pressure | 20–40 mbar |
| Process Gas Inlet | 1, additional optional |
| Test Gas Inlet | 1 per measuring range |
| Relative Gas Humidity | ≤ 95%, non-condensing |
| Supply Voltage | 240 VAC, 50/60 Hz; 110 VAC, 60 Hz |
| Max. Power Consumption | 200 VA |
| Interfaces | 8× SPDT Relays, 3× 4–20 mA, additional bus systems optional |
| T90 Response Time | 15 s |
| Approval (Optional) | NRTL Certification by SGS, UL61010-1, CAN/CSA-C22.2 No. 61010-1 (Customer Reference 710162) |
The CWD product series in comparison
CWD BASIC
Reliable measurement of calorific
and heating value as well as Wobbe index
CWD PLUS
Continuous, highly accurate determination of the Wobbe index
CWD DPC
for use in accordance with Class I Division 2, Groups B, C, D, T4
CWD SPC
Reliable, reproducible measured values in real time for optimum monitoring
CWD EXP
Safe shutdown with changing gas composition Gas composition
CWD HT
The new CWD for precise measured values in the high temperature range
Industry applications
These products can be used in the following sectors.
Iron and steel production
Our appliance series have been used in iron and steel production for many decades.
Biogas
Union Instruments products have proven themselves extensively in biogas upgrading plants.
Petrochemicals and refineries
We produce customized and flexible measurement technology solutions for the petrochemical industry and refineries.
Glass and ceramics
Perfectly coordinated appliance technology for glass and ceramic applications that works both safely and economically.
Natural gas
Our INCA multi-gas analyzers provide efficient solutions for processes in natural gas plants.
Generating energy from waste
Our appliance technology makes an important contribution to the functionality of environmentally friendly and energy-saving system concepts.
Service
We clarify administrative and commercial issues for you.
+49 721 680381-30
Support
You can open a support ticket for technical support for your product.
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Distribution
We prepare quotations for you, clarify questions about invoicing and manage your maintenance contract.
+49 721 680381-20
Downloads
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Brochures, data sheets and application reports – we have all the relevant information for you here.
Industries
Our key application areas at a glance.
We supply a wide range of industrial plants such as steel production, the natural gas industry and biogas producers.
Products
Special products for your industrial application.
Our range includes the INCA, CWD and SIRA product series and the CAM module – combined with top advice and service.